style: satisfy the black gate that was failing the Tests workflow

The Tests workflow was red on every OS and Python version for one reason:
`black --check` found 28 unformatted files. Part predates this branch (the
tui_v3 screens, core/api.py, core/index0.py); part is mine from this session.

Formatting only — verified rather than assumed, because a formatter touching
363 files is exactly where an unnoticed behaviour change would hide:

  - 1223 Python tests pass, unchanged
  - regenerating the fixtures after reformatting the generator produces
    byte-identical output, so no hashed value moved
  - differential fuzz: no divergences

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01Vtx94nXDmNgXEeThUZP4QN

src/tests/test_password_notes_display.py

@@ -27,7 +27,9 @@ def test_password_notes_shown(monkeypatch, capsys):
         pm.vault = vault
         pm.entry_manager = entry_mgr
         pm.backup_manager = backup_mgr
-        pm.password_generator = SimpleNamespace(generate_password=lambda l, i, **_: "pw")
+        pm.password_generator = SimpleNamespace(
+            generate_password=lambda l, i, **_: "pw"
+        )
         pm.parent_seed = TEST_SEED
         pm.nostr_client = SimpleNamespace()
         pm.fingerprint_dir = tmp_path